Mars Reconnaissance Orbiter Extended Science Phase SPK, MRO NAV Solution =========================================================================== Created by Boris Semenov, NAIF/JPL, Wed Aug 16 09:50:30 PDT 2017 Objects in the Ephemeris -------------------------------------------------------- This SPK file contains ephemeris data for the Mars Reconnaissance Orbiter (MRO) spacecraft. The NAIF ID code for MRO is -74. Approximate Time Coverage -------------------------------------------------------- This file covers the following part of the Extended Science Phase of the MRO mission (orbits 50059 through 51225): Start of Interval (ET) End of Interval (ET) -------------------------------- -------------------------------- 2017 APR 01 00:01:10.000 2017 JUL 01 01:01:09.184 Status -------------------------------------------------------- This file was created by merging regular reconstructed OD solution SPK files produced by the MRO NAV team during the Extended Science Phase of the mission. This file was created by NAIF for archiving in the Planetary Data System (PDS). Pedigree -------------------------------------------------------- The original SPK files used to create this file contained only reconstructed trajectory. They were officially delivered to the MRO project data base by the MRO NAV team. The list of the original files data from which has been merged into this file is provided in Appendix 1 of these comments. Segment Boundary Discontinuities -------------------------------------------------------- This SPK file contains a large number of SPK segments that came from original individual SPK files. Although, each segment provides continuous trajectory within the interval that it covers, in general a position and velocity discontinuity exists at the boundary of the segment and the segments whose coverages immediately precede or follow it. The times and magnitudes of these discontinuities are provided in Appendix 2 of these comments. Usage -------------------------------------------------------- This file should be used together with DE414 planetary ephemeris and MAR063 satellite ephemeris since the original SPK files contained subsets of these particular ephemeris in them. Contacts -------------------------------------------------------- If you have questions regarding this data contact Boris V. Semenov (818)-354-8136 Boris.Semenov@jpl.nasa.gov Appendix 1: Original SPK List -------------------------------------------------------- The original SPK files, the data from which has been included into this file, are: spk_psp_rec50156_50078_50156_r-v1.bsp spk_psp_rec50261_50154_50261_r-v1.bsp spk_psp_rec50340_50258_50340_r-v1.bsp spk_psp_rec50442_50337_50442_r-v1.bsp spk_psp_rec50529_50440_50529_r-v1.bsp spk_psp_rec50621_50527_50621_r-v1.bsp spk_psp_rec50711_50619_50711_r-v1.bsp spk_psp_rec50800_50709_50800_r-v1.bsp spk_psp_rec50891_50798_50891_r-v1.bsp spk_psp_rec50981_50889_50981_r-v1.bsp spk_psp_rec51069_50979_51069_r-v1.bsp spk_psp_rec51160_51067_51160_r-v1.bsp spk_psp_rec51263_51158_51263_r-v1.bsp Appendix 2: Segment Boundary Discontinuity Summary -------------------------------------------------------- This SPK file contains a large number of SPK segments that came from original individual SPK files. Although, each segment provides continuous trajectory within the interval that it covers, in general a position and velocity discontinuity exists at the boundary of the segment and the segments whose coverage immediately precede and follow it. The times and magnitudes of these discontinuities are provided in the table included in this Appendix. The top portion of the table contains the name of this SPK file. All descriptive lines in the top portion of the file start with the ``#'' character to allow direct plotting of the data in the freeware ``gnuplot'' application. The table consists of 5 columns. The first column is the orbit number within which a segment boundary with discontinuity occurs. The next column contains the UTC time of that segment boundary. The last three columns (3..5) contain view coordinate frame components -- ``down track'' (this direction is parallel to the velocity vector), ``normal to plane'' (this direction is computed as cross product of position vector by velocity vector) and ``in plane'' (this direction is computed as a cross product of ``down track'' by ``normal to plane'') -- of the difference between the state vectors computed at that UTC time defining segment boundary at which a discontinuity exists. The pairs of segments and discontinuity times are determined using an algorithm that emulates the standard SPK loading priority -- ``last loaded segment takes precedence''. Therefore, the discontinuities summarized in the file are those which a user reading file would actually see. The difference components in the view coordinate frame were computed for each discontinuity using the following algorithm: -- A single state was computed from each pair of segment the J2000 frame at the time of discontinuity. -- For this pair of states, a position difference vector was computed by subtracting the state computed from the segment with higher priority from the state computed from segment with lower priority. Then, a frame transformation matrix rotating these difference vectors from J2000 to the view coordinate frame defined by the state obtained from the higher priority segment was computed, and the position difference vector was rotated to the view frame coordinates using this matrix. The segment boundary discontinuities for this file are: # # Summary of discontinuities at segment boundaries for # SPK file ./mro_psp43.bsp, km: # #ORBNUM BOUNDARY TIME (UTC) DOWNTRK INPLANE NORMAL #------- ----------------------- ------- ------- ------- 50070 2017-04-01T23:46:50.814 -0.002 0.000 -0.002 50078 2017-04-02T13:41:50.814 -0.001 0.000 0.001 50097 2017-04-04T02:08:50.814 -0.004 0.000 -0.003 50117 2017-04-05T15:41:50.814 0.003 0.000 0.003 50134 2017-04-06T23:29:50.814 -0.005 0.000 -0.004 50145 2017-04-07T20:04:50.814 0.001 0.000 0.001 50154 2017-04-08T11:45:50.814 0.002 -0.000 -0.001 50173 2017-04-09T23:57:50.814 0.004 -0.000 0.001 50186 2017-04-10T23:57:50.814 0.000 0.000 0.000 50194 2017-04-11T15:14:50.814 0.003 -0.000 0.001 50209 2017-04-12T19:46:50.814 -0.003 0.000 -0.003 50225 2017-04-14T01:53:50.814 -0.001 0.000 -0.000 50246 2017-04-15T16:59:50.814 -0.000 -0.000 -0.000 50258 2017-04-16T14:17:50.814 0.002 0.000 -0.001 50285 2017-04-18T17:56:50.814 0.000 -0.000 0.000 50301 2017-04-19T23:51:50.814 0.000 -0.000 0.000 50324 2017-04-21T18:58:50.814 -0.003 0.000 -0.002 50337 2017-04-22T18:04:50.814 0.003 -0.000 -0.002 50353 2017-04-24T01:07:50.814 0.002 -0.000 0.002 50369 2017-04-25T07:03:50.814 0.001 -0.000 0.001 50390 2017-04-26T21:25:50.814 -0.000 -0.000 0.000 50411 2017-04-28T13:03:50.814 0.003 -0.000 0.000 50429 2017-04-29T23:17:50.814 -0.002 0.000 -0.002 50440 2017-04-30T18:43:50.814 0.000 -0.000 -0.000 50462 2017-05-02T13:01:50.814 -0.000 -0.000 -0.000 50476 2017-05-03T15:12:50.814 -0.003 0.000 -0.003 50491 2017-05-04T19:16:50.814 0.002 0.000 0.002 50506 2017-05-05T23:19:50.814 0.001 -0.000 0.001 50519 2017-05-06T23:38:50.814 -0.002 0.000 -0.001 50527 2017-05-07T13:26:50.814 0.003 0.000 -0.003 50539 2017-05-08T13:03:50.814 0.004 0.000 0.004 50557 2017-05-09T22:43:50.814 -0.002 0.000 -0.001 50570 2017-05-10T23:02:50.814 -0.000 -0.000 -0.000 50595 2017-05-12T21:47:50.814 0.001 -0.000 0.001 50609 2017-05-13T23:57:50.814 0.001 -0.000 0.001 50619 2017-05-14T17:31:50.814 -0.000 -0.000 0.000 50642 2017-05-16T13:42:50.814 -0.001 0.000 -0.001 50661 2017-05-18T01:14:50.814 -0.001 -0.000 -0.001 50684 2017-05-19T20:15:50.814 0.002 -0.000 0.002 50698 2017-05-20T22:26:50.814 0.002 0.000 0.002 50709 2017-05-21T17:52:50.814 0.000 -0.000 -0.000 50733 2017-05-23T15:35:50.814 0.003 0.000 0.002 50747 2017-05-24T18:05:50.814 -0.001 0.000 -0.001 50763 2017-05-25T23:57:50.814 -0.001 -0.000 -0.001 50775 2017-05-26T22:27:50.814 0.002 0.000 0.002 50788 2017-05-27T22:46:50.815 0.001 -0.000 0.001 50798 2017-05-28T16:19:50.815 -0.002 -0.000 0.002 50814 2017-05-29T23:23:50.815 0.002 -0.000 0.002 50830 2017-05-31T05:19:50.815 -0.003 0.000 -0.002 50847 2017-06-01T13:07:50.815 -0.003 -0.000 -0.003 50865 2017-06-02T22:47:50.815 -0.001 -0.000 -0.001 50878 2017-06-03T23:06:50.815 0.003 0.000 0.003 50889 2017-06-04T18:31:50.815 0.001 0.000 -0.001 50907 2017-06-06T05:23:50.815 -0.000 -0.000 0.000 50930 2017-06-07T23:57:50.815 -0.001 -0.000 -0.001 50942 2017-06-08T22:48:50.815 0.001 0.000 0.001 50952 2017-06-09T17:30:50.815 -0.000 -0.000 -0.000 50965 2017-06-10T17:49:50.815 0.002 0.000 0.002 50979 2017-06-11T18:52:50.815 0.000 -0.000 -0.000 50994 2017-06-12T23:57:50.815 0.000 -0.000 0.000 51004 2017-06-13T18:45:50.815 -0.000 -0.000 -0.001 51014 2017-06-14T13:27:50.815 0.001 0.000 0.001 51034 2017-06-16T02:33:50.815 0.000 -0.000 0.000 51052 2017-06-17T12:31:50.815 -0.000 -0.000 -0.000 51067 2017-06-18T15:27:50.815 -0.001 0.000 0.002 51083 2017-06-19T22:30:50.815 -0.001 0.000 -0.001 51109 2017-06-21T23:08:50.815 -0.002 0.000 -0.002 51132 2017-06-23T17:32:50.815 -0.000 -0.000 0.000 51142 2017-06-24T12:51:50.815 0.002 0.000 0.002 51158 2017-06-25T17:39:50.815 0.002 0.000 -0.002 51179 2017-06-27T10:02:50.815 0.005 0.000 0.006 51190 2017-06-28T06:08:50.815 -0.002 0.000 -0.000 51206 2017-06-29T12:33:50.815 0.000 -0.000 -0.000 51225 2017-06-30T23:57:50.815 -0.001 0.000 -0.001